Hi. From my experience, I would advise you to book your transfer in advance. This is especially handy if you are traveling with kids. As a mom of three boys I know what I'm saying))) Two months ago we went on vacation to Turkey as a family – two adults and three children. We pre-booked a transfer from the airport in Turkey to Belek here https://gettransfer.com/en/directions/turkey. It was the best decision. You won't have to worry about finding a car upon arrival. If you have any questions about the trip, email me and we can discuss everything in detail.
I've never asked myself this question. Perhaps this is done at the legal level?